脑卒中患者痰霍尔曼肠杆菌耐药性及耐药机制的研究

Drug resistant mechanisms of enterobacter hormaechei from sputum of stroke patient

目的探讨脑卒中患者痰霍尔曼肠杆菌耐药性及耐药机制。方法用美国BD公司phoenixTMl00全自动细菌鉴定/药敏仪对临床脑卒中患者痰分离的1株霍尔曼肠杆菌进行鉴定和21种抗菌药物敏感性检测,应用头孢硝噻吩(Ncf)试验检测其β-内酰胺酶(BLs),多底物纸片法分类检测β-内酰胺酶。结果 phoenixTMl00细菌鉴定仪鉴定该菌为霍尔曼肠杆菌,可信度(ID)99%;对阿莫西林/克拉维酸、头孢唑林、头孢西丁耐药,对氨苄西林、氨苄西林/舒巴坦、哌拉西林、哌拉西林/他唑巴坦、头孢他啶、头孢噻肟、氨曲南、头孢吡肟、碳青霉烯类、氨基糖苷类、四环素类、氯霉素、多黏菌素、氟喹诺酮类、磺胺甲噁唑/甲氧苄啶敏感;Ncf试验、邻氯西林协同试验、亚胺培南诱导阳性,克拉维酸、舒巴坦协同试验阴性。结论该脑卒中患者痰霍尔曼肠杆菌临床分离株仅部分β-内酰胺类耐药,其机制为产β-内酰胺酶,耐药表型和邻氯西林协同试验、亚胺培南诱导阳性,推测为产诱导型AmpC酶。

OBJECTIVE To investigate the resistance status and mechanisms of β-lactam of Enterobacter hormaechei from sputum sample of a stroke patient. METHODS The strains were identified and the antibiotic susceptibility was detected by BD＇s phoenixTM 100, the detection of β-lactamase of the strain with nitrocefin test（Ncf） and the variety of β-lactamases with a multi-disk test were performed. RESULTS The strains were identified by phoenixXM100 was E. horrnaechei, ID99%;the strain was resistant to penicillins, amocillin amocillin/clavulanate, cefoxitin, and cephalothin, susceptible to ampcillin, ampcillin /sulbactam, piperacillin, piperaeillin/tazobactam, cefotaxime, ceftazidime, aztreonam, cefepime, imipenem, meropenem, aminoglycosides, tetracyclines, ehloramphenicol, Polymyxin, fluoroquinolon, trimethoprim/sulfamethoxazole; the detection of Ncf, cloxacillin synergy test and imipenem induce test was position,the clavulanate and sulbactam synergy test were negative. CONCLUSION The strains of E. horrnaechei from sputum sample are resistant to some ofβ-lactam. The resistant mechanism of β- lactam is the production of β-lactamase, speculated to the product inducible AmpC β-lactamase by phenotype of drug resistant and cloxacillin synergy test and imipenem induce test.